1. Field of the Invention
The present invention relates to a video reproducing apparatus in which a ratio of a reproducing rate to a recording rate can be changed.
2. Description of Related Art
A video recording/reproducing apparatus for monitoring has been conventionally known that records and reproduces video photographed by a monitoring camera, the video recording/reproducing apparatus being capable of changing the recording rate.
In this type of video recording/reproducing apparatus, a recording operation starts at a previously set recording rate, for example. Thereafter if an unusual situation occurs in the monitored area and an alarm signal is input, then the recording rate automatically increases and the recording operation continues. Therefore, video with different recording rates will be recorded on a recording medium.
Thereafter, the video recorded on the recording medium as described above is displayed on a monitor device and checking of the video is done. If normal reproduction is performed, the checking will take such a long time as the recording time. For example, if normal reproduction is performed of a recording medium on which video is recorded at a rate of ten seconds per one image and thereafter further video is recorded at a rate of 0.2 seconds per one image as shown in FIG. 10(a), then the images will be displayed at a rate of ten seconds per one image and thereafter from the time point when the recording rate is changed to the rate of 0.2 seconds per one image, the images will be displayed at a rate of 0.2 seconds per one image as shown in FIG. 10(b). If the recording time is six hours, the checking will take a long time of six hours.
Checking of video can be done with image display at a rate of 0.1-0.2 seconds per one image. Accordingly, if the recording rate is low, checking is done using fast-forward reproduction.
On the other hand, if a switching rate for image display is high in normal reproduction because of a high recording rate, and therefore the video cannot be checked in detail, then the checking is done using slow reproduction.
However, in the conventional video recording/reproducing apparatus, after a fast-forward reproduction operation starts, the operation is maintained regardless of a change of the recording rate. If the recording rate becomes high during fast-forward reproduction, then depending on that rate, a switching rate for image display will become too high. This has caused a problem of difficulty of checking of video. For example, if fast-forward reproduction of a recording medium on which video is recorded at the recording rates shown in FIG. 10(a) is performed at a rate ten times of the recording rate, then images will be displayed at a rate of one second per one image and thereafter from the time point when the recording rate is changed to the rate of 0.2 seconds per one image, the images will be displayed at a high rate of 0.02 seconds per one image as shown in FIG. 10(c).
Also after a slow reproduction operation starts, the operation is maintained regardless of a change of the recording rate. If the recording rate becomes low during slow reproduction, then depending on that rate, a switching rate for image display will become too low. This has been a problem. For example, if slow reproduction is performed of a recording medium on which video is recorded at a rate of 0.2 seconds per one image and thereafter video is recorded at a rate of ten seconds per one image, then the images will be displayed at a rate of two seconds per one image and thereafter from the time point when the recording rate is changed to the rate of ten seconds per one image, the images will be displayed at an extremely low rate of 100 seconds per one image.